Crankcase ventilator for internal combustion engines



May 18; 1937. R. s. VIVHITTIKIGTON CRANKCASE VENTILATOR FOR INTERNAL COMBUSTION ENGINES Original Filed Jun 17, 1952 ATTORNEY.

Patented May 18, 1937 CRANKCASE VENTILATOR. FOR COMBUSTION ENGINES Ralph S. Whitting ton, Oak Park, 111., assignor to Bendix Products Corporation, South Bend, Ind., a corporation of Indiana Application June 17, 1932, Serial No. 617,827 Renewed October 24, 1936 9 Claims.

This invention relates to the ventilation of the crankcase of an internal combustion engine. One

of the primary objects of this invention is to provide means of reducing the crankcase dilution or the percentage of gasoline which is normally mixed with the lubricant in the crankcase. The further object of this invention is to reduce the oil consumption and leaks which normally take place in the crankcase of an internal combustion engine.

Figure l is the semi-diagrammatic view partly in section of a crankcase ventilating system. Figure 2 is a fragmentary sectional view illustrating an optional control means for this ventilating system.

The common practice has been to circulate air through the crankcase by providing an inlet and outlet at such points that a difference in atmospheric pressure would exist between them when the car was being driven. The method illustrated in Figure 1 has a number of important advantages over prior methods. It is so arranged that any degree of vacuum up to full intake manifold vacuum can be maintained in the crankcase when the motor is designed for this system. Since the vacuum in the crankcase is adjustable it can be made to move varying quantities of air through the crankcase by controlling the size of the openings and leakage into the crankcase. 30 Also, the path that air travels through the crankcase may be controlled by the location of the suction connection and inlet points. Other advantages are positive removal of fumes from the crankcase by drawing them into the intake manifold; greater reduction of crankcase dilution due to the factthat more gasoline will boil off at a given temperature when the air pressure is reduced; reduction of oil consumption by creating a lower than atmospheric pressure on the nating the loss of oil through the conventional crankcase ventilator and by preventing oil leaks from the crankcase due to atmospheric pressure on the outside; reduction of motor noises by 45 closing large openings in the crankcase.

This invention also contemplates the use of a control valve which will entirely out out the ventilating system at low motor speeds in order that the gas coming from the crankcase will not 50 disturb the carburetion of the motor.

Referring then particularly to the drawing, there is shown in Figure 1 a system which is comprised of a passage I which may be any section of the intake manifold, but preferably the 55 carburetor riser near the intake manifold. Into crankcase side of the pistons and also by elimipassage I is tapped'a conduit 2I which at its other end is tapped into the crankcase III. Conduit 2| is provided with lateral extensions 22 and 23 and these extensions contain a bore 24 which slideably receive a valve 4 arranged to divide the conduit 2| into passage 2 and passage 8. Valve 4 is actuated at one end by spring 9 and" at the other end by diaphragm 6 enclosed in casing 25. The passage 8 is provided with jet I3 which is connected to conduit I4, conduit I4 being intended for connection tothe carburetor bowl to supply gasoline. Crankcase I0 is provided with a series of holes as I2 to regulate the location and capacity of air inlets.

In the operation of the system conduit 2| is 15 directly connected to passage I and is subject to the vacuum in the intake system. As soon as the motor is started the vacuum will act through passage 2 through undercut 3 in valve. 4, through passage 5 formed by the bore of extension 23 and a fiat side of valve 4 and on diaphragm 6. The efiect of this vacuum is to allow atmospheric pressure acting through hole I to move diaphragm 6 and valve 4 to shut oil passage 2 from passage 8, but adjustable spring 9 tends to hold valve 4 to open passage 2 to passage 8. The result is that valve 4 opens passage 2 to passage 8 just enough to allow sufilcient vacuum to be applied through passage 5 to diaphragm B to produce a force equal to the force of spring 9 just at the point valve 4 is about to close passage 2 from passage 8. Hole I5 is provided to insure the free movement of piston 4. Therefore the vacuum in passage 8 is determined by the strength of spring 9 and the area of diaphragm 6. Since spring 9 is adjustable it can be adjusted to permit the production of any Vacuum in passage 8 from full manifold vacuum (if the crankcase is tight) to no vacuum at all. Passage 8 passes to crankcase I0 through port I I 49 for the creation of a partial vacuum in the crankcase. This will cause a flow of air and fumes from the crankcase into the intake system, and the rate of this flow will depend upon the size of passage 2 and passage 8, the vacuum 45 created in the crankcase and the nature of leakage and air inlets to the crankcase. Optional holes, as hole I2, may be provided to control the quantity and path of air through the crankcase.

Optional jet t3 may be used in cases where 50 large quantities of air are moved through the crankcase to mix thisair with gasoline. Conduit I4 leads to the carburetor bowl and delivers gasoline through jet I3 in proportion to the vacuum in passage 8 and the velocity of air flowing in 55 threaded extension carried by the conduit and on diaphragm H to close valve I 8 and shut oil vacuum from the crankcase entirely. But this action is opposed by spring I! which holds valve it open at all times, except when thethrottie valve of the carburetor'is nearly closed. Then the vacuum in passage 2-a becomes great enough to allow atmospheric pressure acting through hole It to overcome spring I! and close valve It. It is obvious that spring is can be made of such strength as to provide for the shutting ofl'of this vacuum from the intake manifold at any desired setting of the carburetor throttle valve.

What I claim as my invention is: t

1. 'The combination with the fuel intake system and the crankcase of an internal combustion engine of a conduit connecting said intake system to said crankcase of'said engine, a valve in said conduit between said intake system and said crankcase, an adjustable spring actuating said valve to open said conduit from said intake systemto said crankcase, a diaphragm connected to said valve, a passage from the conduit to the inner face of the diaphragm whereby the vacuum in said system tends, to close said conduit from said crankcase, and means for adjusting said spring to act to open said intake system to said crankcase.

2. The combination with a fuel intake system and the crank case of an internal combustion engine, of means for creating a vacuum in said crank case, said means comprising a conduit connecting the fuel intake system and the crank case, a valve extending transversely of said conduit, said valve being urged towards open position by spring means, a diaphragm carried by the valve in opposed relation to the spring means. and means whereby vacuum created in the conduit will cooperate with said diaphragm and urge the valve towards closed position against the action of the first mentioned spring means.

3. The combination with a conduit connecting the fuel intake system and the crank case of an internal combustion engine, of means for controlling the creation of a vacuum in said crank case, said means comprising a valve movable s,oso,sas

for admitting vacuum from the conduit to one side of the diaphragm for assisting the same in urging the valve towards closed position against the first mentioned spring means.

4."1he combination with the fuel intake system and the crank case of an internal combustion engine, of means for maintaining a vacuum in said crank casing, said means comprising a con duit connecting said fuel intake system and crank case, a slide valve extending transversely across said conduit, springmeans cooperating with the valve on one side of the conduit and urging the same towards closed position, a diaphragm disposed on the opposite side of the conduit and to which the valve is connected and means whereby vacuum created within the conduit will be admitted to the inner side of the diaphragm thereby assisting said diaphragm in overcoming the. action of the spring means at the opposite side of the conduit and in moving the valve towards closed position.

5. A device as set forth in claim 4 including a casing for the diaphragm and carried by the conduit and a passage of communication from the conduit to said casing to the inner side of 8. The combination with the fuel intake system and the crankcase of an internal combustion engine, of a. passage between said crankcase and said intake system, a valve means in said passage, resilient means operating to open said valve means, means responsive to the pressure in said p ssage between said valve'and crank case and operative to close said valve means.

9. A device as set forth in claim '7 including a valve means operated at a predetermined manifold vacuum to close said conduit.

RALPH S. WH'I'I'I'INGTON. 

